It is very common to suffer from shoulder and neck pain after you had a baby, as you are looking down constantly when you are feeding and because you are sleep deprived it is hard to adopt a good posture.
My first tip would be to try to alternate the feeding positions knowing that seating on a chair with your feet down on the floor is the ideal position for your back and neck.
When you are in a seated position think about supporting your low back by placing a rolled up towel or cushion behind your low back. Another cushion or support under your elbows would keep the weight off your baby off your shoulder and allow your neck to relax.
My last tip would be to practice gentle but efficient exercises to strengthen the muscles around your shoulder blades by simply sitting tall and squeezing your shoulder blades together for 15 reps, repeat every hours or so. Gently stretching your neck will also help alleviate the tensions; you can tilt your head to the side and hold down the opposite shoulder (or keep the opposite shoulder down), maintain the position for about 20sec and soap side, repeat each time you are feeding your baby.
Good luck new mums and don’t hesitate to contact me if you have any questions!
Jenny